use strict;
use warnings;
use Bio::SeqIO;

#initialize a bioperl object instance
my $in = Bio::SeqIO->new(-file=> "database_filename.fa", -format=>"fasta"); 
while(my $seq = $in->next_seq){	#read the sequences in the bioperl object
	print $seq->id," ",$seq->seq; #output,ID space-separated from sequences 
	print "\n";
	}